Deathsquitos are easily noticeable because of their noise.
They can be one shot killed even with fists (maybe not with a very low unarmed skill), if you learn the timing you can hit them just before they reach you.
If they one shot you then you are not supposed to be in the plains and it is your fault. They do like 20 damage with max level wolf armor and even less with root chestplate.

Deathsquitos already got nerfed in the past and they are good as they are, not too difficult for the biome they appear in.